One and done.
The CDC and other health agencies recommend adults aim for at least 150 minutes of moderate aerobic activity, along with two muscle-strengthening sessions a week.
However, research suggests you may need much less than that to shed as much fat as through three weekly workouts.
Excess belly fat, namely visceral fat around the abdomen, is closely linked to several health issues like cardiovascular disease, type 2 diabetes and even inflammatory skin conditions.
But the next step to lose belly fat could be as easy as a once-a-week workout.
A study published in the journal Nature Communications found the effects of one weekly session of high intensity interval training on heart health and body fat were comparable to three days of the same exercise.
Researchers at the University of Hong Kong compared adults with abdominal obesity who did one 75-minute session of interval training on a treadmill per week, or split the 75-minute session into three workouts across the week.
The training sessions consisted of four 4-minute high-intensity intervals with resting intervals at three minutes in between, for a total of 25 minutes per session.
The once-a-week group completed each 25-minute session in three sets, with a break of 15 to 30 minutes in between each set.
Total body fat mass, body fat percentage and waist circumference were measured at the beginning of the study, after four months and again at eight months from the start.
Both groups saw significant reductions in total body fat after four months, with the once-a-week group losing around 2.6% and the three workouts a week group losing about 3.5%.
This suggests the total amount of exercise is more important than how exercise is spread throughout the week.
And although fat loss petered out after another four months, participants continued to see reductions in their waistlines, an indicator of less visceral fat.
This “weekend warrior” approach — people who cram exercise into Saturdays and Sundays — could prove beneficial for those in a time crunch.
“Instead of relying solely on high-frequency exercise prescriptions, once-weekly interval training can be considered a feasible and effective alternative,” lead study researcher Professor Parco Siu Ming-fai said.
Weekend-only exercisers lower their risk of more than 200 diseases just as much as those who go to the gym throughout the week, another study found.
High intensity interval training has numerous benefits, even if you leave working out to the weekends.
Regularly upping the intensity can reduce blood pressure, boost metabolism, lower blood sugar levels and burn more calories long after exercise.
And some interval training sessions can even be done in as little as 20 minutes, using only a wall, a chair and your body weight.
However, too much HIIT can backfire by disturbing cortisol levels and leading to less activity, lower body temperature and weight gain.
